Not sure but i guess it would be your great aunt's daughter
If she is your biological granddaughter (not step or adopted), yes.
Step-great-granddaughter
step-granddaughter
Yes, you would be the step-nan (or step-grandmother) to your granddaughter's step-brothers.
step sisters
my step granddaughter Unless you are legally an adoptive parent of your step-son in which case she is your grand-daughter.
Cinderella's step sisters are Drizella and Anastasia.
Diana was her step-granddaughter, so Barbara was Diana's step-grandmother.
step grandaughter is if your mums dad or dads dad marrys another woman that will make her your step nan and you would be her step daughter
Abraham Lincoln had two step-sisters, Matilda and Elizabeth.
your half sisters cousin would be your cousin
The word does not appear in many dictionaries, and is not a standard genealogical term. The usual spelling appears to be hyphenated as "step-granddaughter" rather than stepgranddaughter (as in stepdaughter and granddaughter) as seen in Wiktionary.